The discussion below is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.
Aspects of the present invention relate to a winding mechanism for a sunscreen, for use in an open roof construction for a vehicle comprising a winding tube, being rotatable around a central axis of rotation for winding and unwinding the sunscreen, at least one spring member, for biasing the winding tube in a direction for winding the sunscreen thereon, and a sleeve for protecting said spring member from causing noises.
In prior art sunscreens having a winding mechanism (also known as rollo sunscreens) the spring member, mostly a metal helical torsion spring, is covered by a sleeve preventing the spring member from touching the winding tube. When no sleeve is used, the spring member will rattle or scrape against the inner surface of the winding tube resulting in an unpleasant noise for the users of the vehicle. Such noises can occur when the winding mechanism is operated but also when the vehicle makes certain movements. The prior art sleeves are made of a layer of cloth or rubber like plastic material. However, these sleeves do not fulfill the requirements to a sufficient extent. First of all, it turned out that the sleeves are not sufficiently resistant to wear. Often, the sleeve becomes damaged after a period of use and then starts to rattle within the winding tube. Furthermore the prior art sleeves are not able to dampen the more severe rattling movements of the helical spring member when it is tensioned (wound) and, due to it, has a decreased diameter and thus has more play within the winding tube.